The advent of high density and high performance electronic components has resulted in lengthy process times to build the semiconductor chips and therefore the need for the start of their design early in the design path. Also there is no opportunity to redesign the chips, i.e., `single pass` designs are essential. High performance and density are also driving the need for multichip modules wherein the chips are closely spaced. These multichip modules have numerous interface configurations dependent upon the placement of the chips on the module substrate. Hence we have a conflict between the early chip designs and the unique interface requirements that are determined later in the design flow. This invention resolves the conflict by the use of special circuitry at the inputs to the chips and that can be later reconfigured to match the module requirements.
It is a problem in computer manufacturing that chips which have been put in a component module, such as a TCM, don't test out as they should. There have been schemes to change wires by burning inputs with a laser or a fuse. Circuitry in the gate array field is programmable. However, there still remains the need we recognize that would permit changes in electrical characteristics of chips on a multichip module during the testing process. We have provided a way to do that. In the process of completing our invention, we noted that some existing test methodology related to boundary scan can be incorporated to assist in making the modifications to the input circuitry described herein. These are referenced below: